4 ms·

I think part of the problem is that we still don't have a standard /bin/sh even though there is a written standard. It feels fair to me to suggest that you can

by JNRowe 5y ago

I think part of the problem is that we still don't have a standard /bin/sh even though there is a written standard. It feels fair to me to suggest that you can call dash the working standard on Linux, but you can't trust that beyond Linux systems(and I'm ignoring installs that are busybox-based here too). And that also feels like the problem with extending a script with a few bashisms too, as you're suddenly trying to remember when that feature appeared. Off the top of my head I'm wondering what things won't be available to Mac users because it ships with a pre-GPLv3 bash for example.

jordemort 5y ago
Shellcheck helps a lot with this, I won't write shell without it anymore: https://www.shellcheck.net/ https://www.shellcheck.net/
- DiabloD3 5y ago
  Here here, this has massively improved my code to the point I no longer fear sh and what horrible things I have unleashed.
- declnz 5y ago
  Shellcheck is truly a game-changer, even for people who've been hacking Bash (etc) for 20+ years. Side note: it's also one of (or the ?) most popular Haskell projects out there: https://github.com/koalaman/shellcheck/ https://github.com/koalaman/shellcheck/
  - tym0 5y ago
    Pandoc might be more popular but I agree that Shellcheck is an absolute godsend.
gnubison 5y ago
> I think part of the problem is that we still don't have a standard /bin/sh even though there is a written standard. It feels fair to me to suggest that you can call dash the working standard on Linux, but you can't trust that beyond Linux systems(and I'm ignoring installs that are busybox-based here too). Why do we need a one true shell that implements the standard? Am I misunderstanding you…? The whole point of a standard is that everyone implements it so the different implementations don’t matter (and everyone does implement it, in the case of POSIX shell, minus a couple things like [ -t ] and some bash defaults).
- JNRowe 5y ago
  Given developers testing against shells that implement the spec, and a solid spec, and a variety of implementations that correctly implement that spec then I'm in full agreement with you. However, the moment you add caveats to that description you have, well… caveats to that description. The situation - as I see it - is that we have a spec, and we have systems that ship a /bin/sh that implements something like it. If people are targetting their system's /bin/sh, then they're writing scripts for their /bin/sh implementation not posix compliant shells. For example, my install uses dash which has features beyond the posix spec which I have to eschew to produce portable scripts. As a sibling comment points out shellcheck will point out a lot problems, but it requires people choosing to use it. You only have to dive around /usr/bin for a little while to see its usage isn't universal ;) Of course, if the differences in implementation don't affect your usecase then it simply doesn't matter.

by JNRowe 5y ago

jordemort 5y ago

Shellcheck helps a lot with this, I won't write shell without it anymore: https://www.shellcheck.net/ https://www.shellcheck.net/

DiabloD3 5y ago
Here here, this has massively improved my code to the point I no longer fear sh and what horrible things I have unleashed.
declnz 5y ago
Shellcheck is truly a game-changer, even for people who've been hacking Bash (etc) for 20+ years. Side note: it's also one of (or the ?) most popular Haskell projects out there: https://github.com/koalaman/shellcheck/ https://github.com/koalaman/shellcheck/
- tym0 5y ago
  Pandoc might be more popular but I agree that Shellcheck is an absolute godsend.

gnubison 5y ago

> I think part of the problem is that we still don't have a standard /bin/sh even though there is a written standard. It feels fair to me to suggest that you can call dash the working standard on Linux, but you can't trust that beyond Linux systems(and I'm ignoring installs that are busybox-based here too). Why do we need a one true shell that implements the standard? Am I misunderstanding you…? The whole point of a standard is that everyone implements it so the different implementations don’t matter (and everyone does implement it, in the case of POSIX shell, minus a couple things like [ -t ] and some bash defaults).

JNRowe 5y ago
Given developers testing against shells that implement the spec, and a solid spec, and a variety of implementations that correctly implement that spec then I'm in full agreement with you. However, the moment you add caveats to that description you have, well… caveats to that description. The situation - as I see it - is that we have a spec, and we have systems that ship a /bin/sh that implements something like it. If people are targetting their system's /bin/sh, then they're writing scripts for their /bin/sh implementation not posix compliant shells. For example, my install uses dash which has features beyond the posix spec which I have to eschew to produce portable scripts. As a sibling comment points out shellcheck will point out a lot problems, but it requires people choosing to use it. You only have to dive around /usr/bin for a little while to see its usage isn't universal ;) Of course, if the differences in implementation don't affect your usecase then it simply doesn't matter.